The present invention relates generally to closures, such as doors or windows, and to sealing joints for such closures. More particularly, the invention relates to a sealed joint establishing a weather-tight barrier for closures, to a closure incorporating such sealed joints, and to a method for fabricating a closure of this type.
Exterior closures, such as doors and windows, must generally provide a tight barrier between the outside and the inside of the structure in which they are used. In recent years concern with energy efficiency has intensified the drive toward reliable sealed closures with good heat transfer characteristics. Such closures improve comfort in the interior, climate-controlled living or working space, and contribute to reducing energy usage and thermal losses.
A substantial number of sealing arrangements have been proposed, particularly for sealing around window pane assemblies and between closures and their associated frames. One such arrangement is described in U.S. Pat. No. 5,050,359 issued on Sep. 24, 1991 to Lorge et al. and assigned to the owner of the present invention, Morgan Products Ltd. While such advancements have provided greatly improved energy efficiency, they have not addressed all of the potential sources of leakage through exterior closures, particularly closures comprising an assemblage of multiple elements.
In common multiple-element closures, structural parts such as stiles and rails generally meet to form an outer frame that is structurally secured by such affixing agents as gluing, tacking, or both. A panel, or a number of panels, may be held between the sties and rails by similar means. Most six-panel doors, so-called French doors, and window assemblies are generally constructed in this way. Because the panels, and the joints between the panels in such closures constitute the greatest potential for leakage, improvements in sealing these closures have tended to concentrate on sealing at these locations, while the outer frame has been treated as a solid barrier not requiting additional sealing arrangements.
It has been found, however, that joints between structural elements such as sties and rails can also lead to leakage through the closure. Even where these joints are apparently tightly glued and otherwise tightly affixed, circuitous leak paths are defined between the structural elements that permit air or moisture to penetrate through the frame. The potential for entry of air and moisture is greatly exacerbated by the use of nails, tacks or staples to secure the structural elements. In addition to reducing the efficiency of the closure, over time the intrusion of air and moisture into the frame can result in degradation of the joints and may eventually degrade the entire closure. Where affixing means such as nails, tacks or staples are used to secure the various elements of a composite door additional manufacturing steps are generally required, including covering the affixing means with a cosmetic putty and sanding the putty smooth. Moreover, on good quality wooden closures, even where such putty closely matches the color of the wood, the end result is rarely as aesthetically pleasing as an "all-wood" product.
The present invention is directed to overcoming or minimizing the shortcomings of existing closures in sealingly separating the interior from the exterior of a dwelling or other structure. In particular, the invention is directed to a joint for a closure wherein a sealing member is interposed at the interface between the closure's structural frame members to form a weather-resistant barrier between the inside and the outside of the closure. The invention is also directed to a sealed closure incorporating such joints and to a method for fabricating a closure that results in a unified structure without the use of nails, tacks or staples.